Inson



' NITED STATES PATENT OFFICE.

SAMUEL PAXSON HUTCHIN SON, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE HUTCHINSON STEEL COMPANY, OF NEW YORK, N. Y.

PROCESS OF MANUFACTURINGSTEEL CASTINGS.

SPECIFICATION formingpart of Letters Patent No. 541,812, dated June 25, 1895. Application filed January 15, 1894. Serial No. 496,978. (No specimens.)

To all whom it may concern.-

Be it known that I, SAMUEL PAXSON HUTCH- INSON, a citizen of the United States, residing in Philadelphia, in the county of Philadelphia and State ofPennsylvania, have invented a new and useful Process for Manufacturing Steel Castings from Hard Malleable or Befined Iron Castings, of which the following description is a specification.

My invention has for its object to produce steel castings which can be readily worked and tempered,from hard malleable or refined iron castings; which objectI secure by means of the process as hereinafter described in detail and pointed out in the claims.

The metal to be treated is first placed in suitable receptacles constructed to resist a high degree of heat, and is then covered or embedded in a homogeneous mixture composed of the several ingredients and in substantially the relative proportions as follows: fine White silicious sand, one hundred pounds; powdered charcoal, ten pounds; chloride of sodium, seven and one-half pounds; carbonate of potash or wood ashes of hard wood, seven and one-half pounds; carbonate of lime or floor-spar, one pound, steatite, forty pounds; black oxide of manganese, three pounds, and manganate of potash, one-third of a pound. The receptacles are .then placed in a suitable oven or furnace and subjected to a steady heat of 1,600 to 1,800 until the desired degree of conversion is attained. The'duration of time of heating depends upon the size of the metal being treated and the fineness of steel desired.

In some instances,in order to make my pro cess more efficient, I subject the metal or castings to be treated to a bath of diluted sulphuric acid and dry the same preparatory to heating. This prior bath however, is not an essential element of my invention.

The iron or metal to be treated by the process. substantially as hereinbefore described, when composed of theseveral following in- 5 gredients in substantially the minimum proportions specified, viz: carbon, two; silicon, 0.65; sulphur, 0.02; phosphorus, 0.20; 'man ganese, 0.35, is found to be more susceptible of being readily and quickly converted into the finest steel than it is when otherwise formed.

Having thus set forth my invention, I do not wish to be understood as confining myseltto'the exact proportions as set forth, as

they may be more or less varied according to the skill of the operator and the demands of the metal being treated may require; but

What I do claim, and desire to secure by Letters Patent of the United States, is

1. The herein described method of converting malleable or refined iron castings into steel, which consistsof packing the castings or metal in a mixture composed of sand, charcoal, chloride of sodium, wood ashes, carbonate of lime, steatite, black oxide of manga nese and manganate of potash, and then are posing the same to a steadily controlled high heat, substantially as set forth.

2. The herein described method of convert- 7o ing malleable or refined iron castings into steel, which consists in first subjecting the metal to a sulphuric acid bath, then drying the metal, and exposing it to a steadily controlled high heat in the presence of a mixture 7 5 composed of sand, charcoal, chloride of sodium, 'Wood ashes, carbonate of lime, steatite, black oxide of manganese and manganate of potash, substantially as set forth.

SAMUEL PAXSON HUTCHINSON. Witnesses:

ROBERT HUToHINsoN, CHAS. T. HARVEY. 

